Uniform#

class pylit.models.Uniform(tau, mu)#

Bases: LinearRegressionModel

This is the linear regression model with Uniform model functions.

kernel(omega, param)#

Evaluate the uniform kernel function for a given set of parameters.

This method overrides kernel().

Parameters:
  • omega (ndarray[float64]) – Discrete frequency axis.

  • param (List[float]) – Parameter tuple [k], where k indexes the interval [mu_k, mu_{k+1}] of the uniform kernel support.

Return type:

ndarray

Returns:

Values of the uniform kernel

\[K(\omega; \mu_k, \mu_{k+1}) = \frac{\mathbf{1}_{[\mu_k, \mu_{k+1})}(\omega)}{\mu_{k+1} - \mu_k},\]

ltransform(tau, param)#

Evaluate the Laplace-transformed uniform kernel at the discrete time axis.

This method overrides ltransform().

Parameters:
  • tau (ndarray[float64]) – Discrete time axis.

  • param (List[float]) – Parameter tuple [k], where k indexes the interval [mu_k, mu_{k+1}] of the uniform kernel support.

Return type:

ndarray[float64]

Returns:

Values of the Laplace-transformed uniform kernel

\[\begin{split}\widehat{K}(\tau; \mu_k, \mu_{k+1}) = \begin{cases} 1, & \tau = 0, \\ \frac{e^{-\tau \mu_{k+1}} - e^{-\tau \mu_k}}{-\tau (\mu_{k+1}-\mu_k)}, & \tau \neq 0. \end{cases}\end{split}\]